|By 'transformer box' I assume you mean power supply. Are you sure the one you bought is compatible and that everything is connected properly? |
There should be a group of wires going from the front panel to the motherboard. They'll include the wires for the power switch, power LED and hard drive LED. Are those connected, at least the power switch connector?
You may need to temporarily remove any add-on cards and disconnect the drives. (Do that with the power cord removed) If it then comes on and shows the posting screen then one of the disconnected items must be at fault.
Don't forget to preorder your Hatch green chili for this fall. Many vendors ship world-wide.